This invention relates to CRT display systems for alphanumeric text processing. More particularly, it relates to a CRT display wherein each unitary or whole character is formed and cyclically refreshed as a unit, i.e., before the next succeeding character is either formed or refreshed.
My copending application, "A Text Processing and Display System with Means for Rearranging the Spatial Format of a Selectable Section of Display Data", Ser. No. 46,894, filed on the same date as the present application provides a text processing and display system wherein any portion or section of a block or page of displayed alphanumeric information may be defined and then treated as a separate entity for reformatting purposes, i.e., the margins of the defined sections may be justified, adjusted or the section may be moved in much the same manner as would the overall page or block. The system of said copending application accomplishes this by providing a text processing and display system which comprises a display device which simultaneously displays a block or page having a plurality of lines of alphanumeric characters in ordered display positions, sequentially accessible storage means for storing coded data representations of said displayed characters in a sequence of storage positions spatially corresponding to the positions of the characters in the display block, repetitive display scanning means for traversing said ordered character display positions in successive lines on said display device, and means for sequentially accessing the data representations for each character to be displayed from the storage means in synchronization with the display scanning means. Finally, means are required for applying to the display device signals representative of the whole or unitary character to be displayed at a particular display position prior to the movement of the display scanning means to the next display position so that each whole or unitary character in the displayed block is formed and subsequently refreshed before the next character is so formed and/or refreshed.
The present invention provides the CRT display apparatus wherein said whole or unitary character is formed and/or refreshed before the next whole or unitary character is so formed and/or refreshed. In addition, the present invention directed toward the satisfaction of other existing needs in the alphanumeric CRT display art.
In displays associated with word processing systems wherein the final copy produced by the processing system printer is proportionally spaced, i.e., the alphanumeric characters to be printed and consequently to be displayed are of varying character width and have variable spacing between characters, it would be desirable to have relatively simple and effective apparatus utilizing a minimum of support logic and memory to display such alphanumeric information in the same variable space and size pattern that it will have on the final printed copy.
Likewise, since it is at times desirable in final printed copy to have characters of varying pitch on the same page and even on the same line, there is a need for simple and effective display apparatus for effecting such changes in pitch between displayed alphanumeric characters on the same page or line.